OSTRACODA. 645 
Aparchites millepunctatus.] 
is really much nearer to the forms now referred to the genus than I was inclined to 
believe two years ago. 
I have eight valves of a closely related species or variety from the lower third 
of the Trenton shales, at Minneapolis, and another, slightly longer than the rest, 
from the upper third near Cannon Falls. These specimens are less high than the 
type of A. granilabiatus, the ventral margin being less convex. The anterior end also 
is a trifle narrower, and the convexity of the valves somewhat less, while none of 
them show anything of the granulose surface ornament nor of the marginal papille. 
These specimens may provisionally be known as var. NEGLECTUS. 
The straight back and dorsal angles will at once distinguish both the species 
and variety from A. ellipticus. 
Formation and locality.—Upper. third of the Trenton shales, St. Paul, Minnesota. Var. neglectus 
occurs in the lower third of the shales at Minneapolis. 
APARCHITES MILLEPUNCTATUS Ulrich. 
PLATE XLV, FIGS. 16-18. 
Leperditia millepunctata ULRICH, 1892. Amer. Geol., vol. x, p. 268. 
Size.—(R. V.) Length 1.57 mm.; hight 1.0 mm.; thickness 0.42 mm. 
Valves subelliptical, dorsal margin long, straight; ends rounded from the dorsal 
angles, equal; ventral edges bevelled inward; point of greatest convexity a little 
behind and beneath the middle; surface very finely punctate. 
+ This species is smaller than A. granilabiatus, but relatively longer, and more 
uniformly convex. In its outline it is similar to Leperditella aquilatera Ulrich, from 
the Birdseye limestone of Kentucky (see fig. 46, p. 636), but it is a little higher, has 
beveled and not overlapping edges, and a punctate surface which is wanting in that 
species. 
Formation and locality —Lower or middle third of the Trenton shales, near Fountain, Minnesota. 
APARCHITES FIMBRIATUS Ulrich. 
PLATE XLV, FIGS. 10—12. 
Leperditia jfimbriata ULRICH, 1892. American Geologist, vol. x, p. 268. 
SizeE.—(R.V.) Length 1.88 mm.; hight 1.28 mm.; thickness 0.44 mm. 
Valves suboval, moderately and almost uniformly convex; back straight, nearly 
two-thirds as long as the valve; dorsal angles sharp, a slight swelling of the surface 
immediately beneath them causing them to appear somewhat prominent; ends 
nearly equally rounded, the posterior a little the wider. The entire ventral border 
and the ends, excepting the upper third on each side, with a fringe consisting of 
long, almost paliform, processes, separated by intervals of 0.1 mm. or less. 
